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nasty-shy [4]
3 years ago
7

Simplify 9 − (−4). −13 −5 5 13

Mathematics
2 answers:
andrew11 [14]3 years ago
8 0
- - = +   9-(-4)= 9+4 so minus minus becomes plus. and 13 is the answer.
agasfer [191]3 years ago
5 0
When subtracting integers, you add by the opposite sign. Right now, you are subtracting 9 by -4. Change this to adding 9 + (+4). Of course, 9 + 4 = 13.

The answer is 13 or D.
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Answer:

A sample of 997 is needed.

Step-by-step explanation:

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In which

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The margin of error is of:

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This means that \pi = 0.08

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How large a sample is needed in order to be 98% confident that the sample proportion will not differ from the true proportion by more than 2%?

This is n for which M = 0.02. So

M = z\sqrt{\frac{\pi(1-\pi)}{n}}

0.02 = 2.327\sqrt{\frac{0.08*0.92}{n}}

0.02\sqrt{n} = 2.327\sqrt{0.08*0.92}

\sqrt{n} = \frac{2.327\sqrt{0.08*0.92}}{0.02}

(\sqrt{n})^2 = (\frac{2.327\sqrt{0.08*0.92}}{0.02})^2

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Rounding up:

A sample of 997 is needed.

3 0
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Answer:

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Step-by-step explanation:

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